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1.
Acta Crystallogr E Crystallogr Commun ; 80(Pt 9): 942-946, 2024 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-39267874

RESUMEN

The cyclic peptide cyclo(Val-Leu-Leu-d-Phe-Pro)2 (peptide 1) was specifically designed for structural chemistry investigations, drawing inspiration from Gramicidin S (GS). Previous studies have shown that Pro residues within 1 adopt a down-puckering conformation of the pyrrolidine ring. By incorporating fluoride-Pro with 4-trans/cis-isomers into 1, an up-puckering conformation was successfully induced. In the current investigation, introducing hy-droxy-prolines with 4-trans/cis-isomer configurations (tHyp/cHyp) into 1 gave cyclo(Val-Leu-Leu-d-Phe-tHyp)2 methanol disolvate monohydrate, C62H94N10O12·2CH4O·H2O (4), and cyclo(Val-Leu-Leu-d-Phe-cHyp)2 monohydrate, C62H94N10O12·H2O (5), respectively. However, the puckering of 4 and 5 remained in the down conformation, regardless of the geometric position of the hydroxyl group. Although the backbone structure of 4 with trans-substitution was asymmetric, the asymmetric backbone of 5 with cis-substitution was unexpected. It is speculated that the anti-cipated influence of stress from the geometric positioning, which was expected to affect the puckering, may have been mitigated by inter-actions between the hydroxyl groups of hy-droxy-proline, the solvent mol-ecules, and peptides.

2.
Sci Total Environ ; 948: 174805, 2024 Oct 20.
Artículo en Inglés | MEDLINE | ID: mdl-39019265

RESUMEN

Shipping is a major contributor to anthropogenic emissions, exerting complex effects on both the environment and climate. To improve the air quality of coastal areas, China adopted an upgraded policy on domestic emission control areas (DECA 2.0) for shipping in December 2018, which expanded the geographical scope of ECAs from three designated heavy-traffic coastal regions to the entire 12 nautical mile-territorial seas and also introduced more stringent ship emission requirements. Based on data from the Automatic Identification System, this study first evaluates the environmental effects of ship emissions' reduction brought by DECA policy 2.0. Results reveal that implementation of DECA policy 2.0 has resulted in a cumulative reduction (2019-2021) of 8.43 × 105 tons, 1.3 × 105 tons, and 1.49 × 105 tons of sulfur dioxide (SO2), particulate matter <2.5 µm diameter (PM2.5) and PM <10 µm (PM10) emissions, respectively. Based on the external cost method, we further monetize the environmental benefits arising from reduction of air pollution emissions, averaging $3.6 billion USD per year. This number equates to ca. 4 % of the total output value of China's marine transportation industry over the three-year period. Finally, we calculate the fuel replacement cost arising from the implementation of DECA policy 2.0, which is on average $1.23 billion USD. This indicates that the net environmental benefits of DECA policy 2.0 equate nearly double the associated costs.

3.
Environ Sci Technol ; 58(9): 4237-4246, 2024 Mar 05.
Artículo en Inglés | MEDLINE | ID: mdl-38386008

RESUMEN

Concentrations of polybrominated diphenyl ethers, hexabromocyclododecane (HBCDD), and novel brominated flame retardants (NBFRs) were measured in indoor dust, indoor air, and outdoor air in Birmingham, UK. Concentrations of ΣBFRs ranged from 490 to 89,000 ng/g, 46-14,000 pg/m3, and 22-11,000 pg/m3, respectively, in UK indoor dust, indoor air, and outdoor air. BDE-209 and decabromodiphenyl ethane (DBDPE) were the main contributors. The maximum concentration of DBDPE (10,000 pg/m3) in outdoor air is the highest reported anywhere to date. In contrast with previous studies of outdoor air in Birmingham, we observed significant correlations between concentrations of tri- to hepta-BDEs and HBCDD and temperature. This may suggest that primary emissions from ongoing use of these BFRs have diminished and that secondary emissions (e.g., evaporation from soil) are now a potentially major source of these BFRs in outdoor air. Conversely, the lack of significant correlations between temperature and concentrations of BDE-209 and DBDPE may indicate that ongoing primary emissions from indoor sources remain important for these BFRs. Further research to clarify the relative importance of primary and secondary sources of BFRs to outdoor air is required. Comparison with earlier studies in Birmingham reveals significant (p < 0.05) declines in concentrations of legacy BFRs, but significant increases for NBFRs over the past decade. While there appear minimal health burdens from BFR exposure for UK adults, dust ingestion of BDE-209 may pose a significant risk for UK toddlers.


Asunto(s)
Contaminación del Aire Interior , Retardadores de Llama , Hidrocarburos Bromados , Adulto , Humanos , Contaminación del Aire Interior/análisis , Polvo/análisis , Monitoreo del Ambiente , Retardadores de Llama/análisis , Éteres Difenilos Halogenados/análisis , Reino Unido , Bromo/análisis
4.
Int J Equity Health ; 23(1): 14, 2024 Jan 23.
Artículo en Inglés | MEDLINE | ID: mdl-38263155

RESUMEN

BACKGROUND: The pandemic has put at risk the social and emotional development of children on account of the paucity of arenas for social interaction. This study from Kerala, India was conducted to assess the resilience factors, behavioural concerns, psychological distress symptoms among the children aged 3 to 5 years. We also tried to look into the lost opportunities that could have aided the social and emotional development of children like peer interaction, child care hours. METHODS: The cross-sectional study was conducted among the children aged 3 to 5 years. A total of 535 children attending the immunisation clinics were enrolled by consecutive sampling. Devereux Early Childhood Assessment P2 (DECA P2) questionnaire was used to assess the levels of resilient factors and behavioural concerns in the study population. RESULTS: We observed a high proportion of children in the area of need category of protective factors under DECA P2. The proportion of children falling under area of concern was 64.5%, 49%, 68.4% for attachment/relationship, self-regulation, and initiative respectively. 24.9% study subjects have a behavioural concern score that puts them in the area of need category. The logistic regression model we created identified 'Male Gender,' 'Mothers could spend only less time for child care' and 'electronic devices used as pacifier' as significant predictors for belonging to Area of need Behavioural Concerns T score category. CONCLUSION: A large proportion of children aged between 3 to 5 years with reported behavioural concerns and lack of protective factors for socioemotional development. This can be attributed partly to the ongoing pandemic and its associated restrictions. The increased child care hours invested by parents or grandparents could have sized down the full impact that the pandemic would have had on the socio emotional development of the child. Increased time spent using electronic devices coupled with dwindled opportunities for interaction with peers have been notable challenges.


Asunto(s)
COVID-19 , Distrés Psicológico , Resiliencia Psicológica , Preescolar , Humanos , Masculino , Pandemias , Estudios Transversales , Factores Protectores , India
5.
J Biomol Struct Dyn ; : 1-15, 2023 Oct 30.
Artículo en Inglés | MEDLINE | ID: mdl-37904339

RESUMEN

Tinospora cordifolia has a variety of compounds, and some of these compounds may have anti-inflammatory and antioxidant properties. In the present study, we identified the compounds in the leaf extract of T. cordifolia through Gas Chromatography-Mass Spectrometry (GC-MS) analysis and found the various metabolites. The compounds are screened virtually using a machine learning model, followed by molecular docking and simulation study to identify top-hit compounds as cyclooxygenase (COX) inhibitors. The molecular docking revealed that the compound 7,9-Di-tert-butyl-1-oxaspiro (4,5) deca-6,9-diene-2,8-dione (CID:545303) exhibited the lowest binding energies of -7.1 and -6.8 kcal/mol against COX 1 and COX 2 respectively. The interactions are favored by hydrogen bonding and hydrophobic interaction inside the binding pocket. The 100 ns MD simulation study for these compounds was performed to know the stability and found the RMSD around 2 Å and around 1.0 Å with minimal fluctuations indicating a stable complex throughout the simulation of 100 ns. Based on these findings, we proposed 7,9-Di-tertbutyl- 1-oxaspiro (4,5) deca-6,9-diene-2,8-dione could be used as a dual inhibitor of COX enzymes and a drug-like molecule for treating inflammation after evaluation of their biological properties. The methanolic extract of T. cordifolia was subjected to in vitro DPPH, ABTS, nitric oxide, anti-microbial, COX, and LOX inhibition activity. The results exhibited possible positive effects against the above activities.Communicated by Ramaswamy H. Sarma.

6.
Acta Crystallogr E Crystallogr Commun ; 79(Pt 9): 786-790, 2023 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-37693668

RESUMEN

The structures of three racemic (tetra-hydro-[1,3]dioxino[5,4-d][1,3]dioxin-4-yl)methanol derivatives are reported, namely, 4-[(methyl-sulfon-yloxy)meth-yl]-2,4,4a,6,8,8a-hexa-hydro-[1,3]dioxino[5,4-d][1,3]dioxine, C8H14O7S, 1, 4-[(benz-yloxy)meth-yl]-2,4,4a,6,8,8a-hexa-hydro-[1,3]dioxino[5,4-d][1,3]dioxine, C14H18O5, 2, and 4-[(anilinocarbon-yl)meth-yl]-2,4,4a,6,8,8a-hexa-hydro-[1,3]dioxino[5,4-d][1,3]dioxine, C14H17NO6, 3. Mesylate ester 1 at 173 K has triclinic P symmetry and both benzyl ether 2 at 173 K and phenyl urethane 3 have monoclinic P21/c symmetry. These structures are of inter-est because of the conformation of the cis-fused tetra-oxadeca-lin ring system. This cis-bi-cyclo-[4.4.0]decane ring system, i.e. cis-deca-lin, can undergo conformational equilibration. In the two most stable conformers, both six-membered rings adopt a chair conformation. However, there are significant consequences in these two stable conformers, with heteroatom substitution at the 1,3,5,7-ring positions as described. Only one conformation, denoted as 'concave' or 'inside', is found in these crystal structures. This is consistent with previously reported structures of the 1,1-geminal dihy-droxy aldehyde and tosyl-ate analogs.

7.
Water Res ; 243: 120306, 2023 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-37566957

RESUMEN

This study assesses the formation and stability of the water contaminant 7,9-di­tert­butyl­1-oxaspiro(4,5)deca-6,9-diene-2,8­dione ([1]) which repeatedly occurs in the migration waters of cross-linked polyethylene (PE-X) pipes. In aqueous solution [1] is partially transformed to 3-(3,5-di­tert­butyl­1­hydroxy-4-oxo-2,5-cyclohexadien-1-yl)propionic acid ([2]). For a better understanding of the formation of [1] and its transformation into [2] an analytical method was established to allow the analysis of both species separately. Because of thermal instability [2] cannot be detected with GC-MS. Therefore, two methods were validated for a reliable and reproducible quantification: GC-MS for [1] and HPLC-MS/MS for both [1] and [2]. Comparative measurements of migration waters from PE-X pipes using GC-MS and HPLC-MS/MS methods showed that the concentrations of [1] detected with GC-MS corresponds to the sum of [1] and [2] measured with HPLC-MS/MS. In the migration waters [1] was detected in higher concentrations than [2]. The highest concentrations of [1], detected with GC-MS, were > 300 µg/L. The longer the materials are stored without contact with water, the more [1] is measured in the migration waters. Most of the previous values reported in the literature for [1] were based on semi-quantification. Hence, we compared results of the semi-quantitative determination according to EN 15768 with those of a quantitative method with a standard. The results gained with the semi-quantitative method represent less than 50% of the quantified values for the amount leaching from the pipes, which means that the semi-quantification method according to EN 15768 leads to a significant underestimation of [1]. Finally, stability assessment showed that [1] developed an equilibrium with [2] under acidic conditions, whereas it will completely be transferred to [2] at pH 10. At pH 7, it takes more than 50 days for [1] to reach an equilibrium with [2]. However, at increasing the temperature to 60 °C, [1] will be rapidly transformed into [2]. Besides [1] and [2], other currently unknown degradation products are formed. As there is no comprehensive toxicological assessment for both substances available today, our findings underline the need for regulatory consequences.


Asunto(s)
Polietileno , Espectrometría de Masas en Tándem , Cromatografía Liquida , Cromatografía Líquida de Alta Presión , Agua
8.
J Hazard Mater ; 459: 132223, 2023 Oct 05.
Artículo en Inglés | MEDLINE | ID: mdl-37586240

RESUMEN

Decabromodiphenyl ether (Deca-BDE) was officially listed in Annex A of the Stockholm Convention for persistent organic pollutants (POPs). It is necessary to establish its emission inventory to help reduce Deca-BDE contamination in the environment. We established a comprehensive Deca-BDE emission inventory in China. The results reveal that, from 2015 to 2017, the Deca-BDE emissions in its production source (source I) were less altered but increased annually in flame retarded plastics processing (source II), Deca-BDE-containing products usage (source III), and electronic waste (e-waste) treatment (source IV). We show that Deca-BDE emissions declined significantly in sources I and II but grew in source III and source IV from 2017 to 2018. We set up the provincial emission inventory to a gridded map on a spatial resolution of 0.25°× 0.25° latitude/longitude. The gridded inventory was incorporated into ChnMETOP model to simulate Deca-BDE concentrations in air and soil, and the modeled concentrations were compared to field-sampling data. The results show that the Deca-BDE emission inventory developed in this study agreed well with observed data, demonstrating that the Deca-BDE inventory in China developed in the present study is reliable. The inventory provides a support for quantifying human exposure risk to Deca-BDE and developing effective mitigation measures to mitigate Deca-BDE emissions.

9.
Appl Radiat Isot ; 191: 110505, 2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-36371866

RESUMEN

The MAGIX code (a French acronym standing for Automatic Gamma and X-ray Measurement) is a software developed to analyze γ/X spectra on the topic of severe accident diagnosis. Indeed, the gamma spectra obtained after a severe reactor core accident are complex because they are composed of hundreds of lines of short-lived fission products and Fukushima accident demonstrated a lack in robustness of data interpretation during a crisis. MAGIX allows a complete and entirely automatic analysis of the spectra, with identification of radionuclides and calculation of activities. It can analyze spectra measured by detectors with excellent resolution such as HPGe detectors as well as detectors with medium resolution (e.g. CZT and LaBr3). For most detectors, the analysis of the spectra can be done without a detection efficiency curve because its process can include the calculation of a relative detection efficiency. MAGIX accepts spectra corresponding to any experimental setup (energy slope, energy range, resolution, absorber, etc.). However, these experimental conditions can have an impact on the quality of the results. Results on spectra simulated in different configurations showed that the analysis of the HPGe spectrum with the user defined efficiency and with the MAGIX detection efficiency were close. Furthermore, they also showed that the accuracy of activities was similar with increasing energy slopes but decreased with resolution degradation, with fewer correctly identified radionuclides in this case.


Asunto(s)
Radioisótopos , Programas Informáticos , Método de Montecarlo , Rayos gamma , Radioisótopos/análisis , Rayos X
10.
IUCrdata ; 7(Pt 6): x220627, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-36339897

RESUMEN

The title compound, (C4H12N5)4(C2H7N4O)2[V10O28]·4H2O, is a by-product obtained by reacting ammonium metavanadate(V), metformin hydro-chloride and acetic acid in the presence of sodium hypochlorite, at pH = 5. The crystal structure comprises a deca-vanadate(V) anion (V10O28)6- lying on an inversion centre in space group P , while cations and solvent water mol-ecules are placed in general positions, surrounding the anion, and forming numerous N-H⋯O and O-H⋯O hydrogen bonds. Metforminium (C4H12N5)+ and guanylurea (C2H7N4O)+ cations display the expected shape. Inter-estingly, in physiology the latter cation is known to be the main metabolite of the former one. The reported structure thus supports the role of sodium hypochlorite as an oxidizing reagent being able to degrade metformin hydro-chloride to form guanylurea.

11.
Cureus ; 14(9): e28885, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-36225450

RESUMEN

Background and objective Employing the POPBL (Patient-Oriented Problem-Based Learning) method to teach students offers a fresh take on the classroom experience. It helps to enhance the motivation of the students, improves knowledge, self-learning behavior, and clinical reasoning, and also helps to promote long-lasting memory. In our medical college, we adopted a newer technology-oriented method with the use of case history, laboratory findings, a gross specimen of the same case, microscopic live sessions via Deca and Penta head microscopes, television, and microscopic camera. In light of this, in this study, we aimed to develop a patient- and technology-oriented new Problem-Based Learning (PBL) method and compare its effectiveness with the traditional tutorial method. Materials and methods A total of 149 second-year MBBS students were enrolled in the study. Consent was taken from all students. A total of eight systems of systemic pathology from the second-year MBBS curriculum were selected. Of the eight systems, four were covered under POPBL with gross and microscopic features associated with the help of newer-generation audiovisual aids, and the other four systems were covered under the traditional tutorial/lecture method. The evaluation was performed using prevalidated objective types of questions after exposure of about one week. The objective was to evaluate and compare the outcomes and students' performance between these two sets of pathology systems. Results Students gave excellent responses. Performance (87.92% of students had scores >75%) and attendance (94.14%) parameters with respect to POPBL gross and microscopic features associated with the help of newer-generation audiovisual aids like Deca and Penta head microscopes were superior compared to the traditional tutorial/lecture method, where 53.02% of students scored more than 75% and the attendance was 76.12%. The difference in attendance was also statistically significant (p=0.05). Conclusion Using POPBL instead of standard tutorial/lecture methods leads to better outcomes. Students also found POPBL more appealing than standard lectures. It is a student-centered method that provides a significant level of motivation and encourages active participation among students. The efficacy of this new way of teaching and demonstrating will attract more students to this method.

12.
Acta Crystallogr E Crystallogr Commun ; 78(Pt 5): 481-484, 2022 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-35547794

RESUMEN

The crystalline product (NH4)2[Zn(C3H7NO)(H2O)5]2[V10O28]·4H2O was success-fully isolated from an H2O/DMF solvent combination by evaporation at ambient temperature. The salt crystallizes in the P21/n space group. Imidazole, initially used in the synthesis but not present in the product, and DMF solvent appear to affect the synthesis and crystallization as structural-directing agents. In the title compound, the complex cation [Zn(H2O)5(DMF)]2+ acts as a counter-ion without being directly coordinated to the deca-vanadate anion. An extensive framework of hydrogen bonds integrates the whole architecture as evidenced by X-ray crystallography. The polyoxometalate [V10O28]6- lies on a center of symmetry while the complex cation [Zn(H2O)5(DMF)]2+ links three adjacent anions through a set of 2 + 2 + 3 hydrogen bonds.

13.
Acta Crystallogr E Crystallogr Commun ; 77(Pt 2): 148-152, 2021 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-33614144

RESUMEN

The square-planar nickel(II) title complex, [Ni(C24H36F2N6)](ClO4)2 or [NiL](ClO4)2 (L = 3,10-bis-(4-fluoro-pheneth-yl)-1,3,5,8,10,12-hexa-aza-cyclo-tetra-deca-ne) was synthesized by a one-pot reaction of template condensation and its X-ray crystal structure was determined. The nickel(II) ion lies close by a twofold axis and the complex displays whole-mol-ecule disorder. Ligand L, a hexa-aza-cyclo-tetra-decane ring having 4-fluoro-phenethyl side chains attached to uncoordinated nitro-gen atoms, adopts a trans III (R,R,S,S) configuration. The average Ni-N bond distance is 1.934 (9) Å, which is quite similar to those of other nickel(II) complexes with similar ligands. The nickel(II) ion is located 0.051 (7) Šabove the least-squares plane through the four coordinated N atoms. The average C-N bond distance and C-N-C angle involving uncoordinated nitro-gen atoms are 1.425 (12) Šand 118.0 (9)°, respectively, indicating a significant contribution of sp 2 hybridization for these N atoms. The inter-molecular N-H⋯O, C-H⋯O/F hydrogen bonds of the complex form a network structure, which looks like a seamless floral lace pattern.

14.
IUCrdata ; 6(Pt 6): x210634, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-36337320

RESUMEN

The title compound, (NH4)4(C4H12N5)2[V10O28]·6H2O, crystallizes with the deca-vanadate anion placed on an inversion centre in space group P . This anion is surrounded by a first shell of ammonium cations and water mol-ecules, forming efficient N-H⋯O and O-H⋯O hydrogen bonds. A second shell includes metforminium monocations with a twisted geometry, also forming numerous inter-molecular hydrogen bonds. The complex three-dimensional network of non-covalent inter-actions affords a crystal structure in which the cations and anions are densely packed.

15.
Acta Crystallogr E Crystallogr Commun ; 76(Pt 11): 1775-1778, 2020 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-33209352

RESUMEN

The 4-methyl-pyridine (4-Mepy) based dimeric copper(II) carboxyl-ate complex [Cu2(C10H19O2)4(C6H7N)2] or [Cu2(µ-O2CC9H19)4(4-Mepy)2] crystallizes with triclinic (P ) symmetry. The two CuII ions exhibit a distorted square-pyramidal environment and are connected into a centrosymmetric paddle-wheel dinuclear cluster [Cu⋯Cu = 2.6472 (8) Å] via four bridging carboxyl-ate ligands arranged in the syn-syn coordination mode. The apical positions around the paddle-wheel copper centers are occupied by the N atoms of the 4-methyl-pyridine ligands. The structure exhibits disorder of the terminal alkyl carbon atoms in the deca-noate chains.

16.
Sci Total Environ ; 748: 141328, 2020 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-32798868

RESUMEN

Iron-redox cycling microorganisms are important for understanding the biogeochemical iron and play key roles in zero-valent iron (ZVI) mediated environmental bioremediation. Their influence on ZVI oxidation coupling with organic contaminant removal is of particular interest but is still poorly understood. The objective of this research was to study microbial redox cycles of iron in ZVI oxidation and deca-brominated diphenyl ether (deca-BDE) removal. It was found that iron-oxidizing bacteria (IOB) enhanced ZVI oxidation by using iron as the sole electron donor. Iron-reducing bacteria (IRB) with high activity of Fe (III) reduction, also significantly accelerated rather than inhibited ZVI oxidation. ZVI oxidation activity was increased from 3.42% to 24.28% by IOB and 19.49% by IRB. When deca-BDE was present in the medium, ZVI oxidation activity by IOB and IRB was increased from 2.67% to 48.33% and 64.33%, respectively. However, no co-accelerating effect of IOB and IRB occurred but rather a neutralizing influence on ZVI oxidation was detected with iron-redox cycling bacteria (IORB). ZVI oxidation activity by IORB only increased to 13.14% and 37.0% in the absence and presence of deca-BDE, respectively. Meanwhile, IRB also exhibited the highest removal activity of deca-BDE. Approximately 71.67% of deca-BDE was removed by IRB, compared to 18.91% by IOB and 43.24% by IORB. Deca-BDE significantly influenced the effects of iron-metabolizing microorganisms on ZVI oxidation by altering the composition of microbial communities. Pseudomonas, Paenibacillus, and Sporolactobacillus were the key genera influencing ZVI oxidation and deca-BDE removal. Sporolactobacillus was firstly reported to be able to stimulate both ZVI oxidation and deca-BDE removal. Pseudomonas accelerated ZVI oxidation but had no significant contribution to deca-BDE removal. However, Paenibacillus inhibited both Fe(III) reduction and deca-BDE removal. It is expected that continuous integration of ZVI oxidation and organic contaminant removal can be achieved by regulating the key genera in iron-metabolizing microbial communities.


Asunto(s)
Bifenilos Polibrominados , Contaminantes Químicos del Agua , Éter , Éteres Difenilos Halogenados , Hierro , Oxidación-Reducción
17.
Acta Crystallogr E Crystallogr Commun ; 76(Pt 3): 324-327, 2020 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-32148869

RESUMEN

The crystal structure of title salt, C14H36N4 4+·2ClO4 -·2Cl-, has been determined using synchrotron radiation at 220 K. The structure determination reveals that protonation has occurred at all four amine N atoms. The asymmetric unit contains one half-cation (completed by crystallographic inversion symmetry), one perchlorate anion and one chloride anion. A distortion of the perchlorate anion is due to its involvement in hydrogen-bonding inter-actions with the cations. The crystal structure is consolidated by inter-molecular hydrogen bonds involving the 1,4,8,11-tetra-methyl-1,4,8,11-tetra-azonia-cyclo-tetra-decane N-H and C-H groups as donor groups, and the O atoms of the perchlorate and chloride anion as acceptor groups, giving rise to a three-dimensional network.

18.
Environ Pollut ; 263(Pt A): 114643, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-33618465

RESUMEN

China has been in the implementation phase of Domestic Ship Emission Control Areas (DECAs) regulation to reduce emissions of air pollutants from ships near populated areas since 2016. The Yangtze River Delta (YRD) is one of the busiest port clusters in the world, accounting for 11% of global seaborne cargo throughput, so future improvements in shipping emission controls may still be important in this region. To assess the impact of future ship emissions on air quality of coastal areas, this study evaluates emissions reductions and air quality in 2030 for three scenarios (business as usual, stricter regulations, and aspirational policies) representing increasing levels of control compared with a base year of 2015. We projected ship emissions in the region using a bottom-up approach developed in this study and based on the historical ship automatic identification system (AIS) activity data. We then predicted air quality across the YRD region in 2030 using the Community Multiscale Air Quality (CMAQ) model. The annual average contributions of ship emissions to ambient PM2.5 would decrease by 70.9%, 80.4%, and 86.2% relative to 2015 under the three scenarios, with the largest reductions of more than 4.1 µg/m3 near Shanghai Port under the aspirational scenario. Reductions in ship emissions generally led to lower levels of PM2.5, particularly in most of the coastal cities in the YRD. Compared with a business-as-usual approach the aspirational scenario reduced SO2, NOx and PM2.5 concentrations from shipping by 71.8%, 61.1% and 52.5%, respectively. It was also more effective than the stricter regulation scenario, suggesting that the requirement to use 0.1% sulfur fuel within a 100Nm DECA would have additional benefits to ambient PM2.5 concentrations beyond 12Nm DECA area. This study provides evidence to inform deliberations on the potential air quality benefits of future control policies for ship emissions in China.


Asunto(s)
Contaminantes Atmosféricos , Contaminación del Aire , Contaminantes Atmosféricos/análisis , Contaminación del Aire/análisis , China , Ciudades , Monitoreo del Ambiente , Material Particulado/análisis , Ríos , Navíos , Emisiones de Vehículos/análisis
19.
Neuropsychiatr Dis Treat ; 15: 3375-3385, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31824161

RESUMEN

BACKGROUND: The Devereux Early Childhood Assessment for Toddlers (DECA-T), which is one of the few standardized, norm-referenced behavioral rating scales related to young children's mental health, resilience, and social-emotional development, was developed for toddlers aged between 18 and 36 months. OBJECTIVE: The aim of this study was to test the clinimetric properties of the Chinese (Traditional) version of the DECA-T (C-DECA-T) using a classical test theory analysis and an item response theory analysis. METHODS: Seventy-five community-based toddlers aged from 18 to 36 months and 50 clinic-based participants recruited in hospitals in northern Taiwan participated in this study. Social-emotional competence was assessed by the C-DECA-T and children's behavior problems were rated via the Child Behavior Checklist 1.5 to 5 (CBCL/1.5-5). Homogeneity of the C-DECA-T was assessed by Mokken analysis; sensitivity and specificity were assessed via receiver operating characteristic curve. RESULTS: The results showed the C-DECA-T demonstrated good test-retest reliability (r=0.8) and high internal consistency (Cronbach's alpha = 0.94). Inter-rater reliability between father and mother was fair (ICC = 0.46). Convergent validity of the CBCL/1.5-5 total behavior problems (r=-0.26) demonstrated acceptable psychometric performance. The overall measure of the sampling adequacy of the C-DECA-T assessed by principal component analysis was 0.93. Mokken scale analysis showed the 36-items of the C- DECA-T formed a weak unidimensional scale (Hs =0.35), supporting its construct validity. The area under curve of the C-DECA-T in prediction of social-emotional disturbance was 0.70. The optimal cutoff of the Total Protective Factor score of the C-DECA-T was a T score of 40.1 (T40.1), with a sensitivity of 95% and a specificity of 68%. Item 2 ("show affection for a familiar adult") and item 33 ("calm herself/himself") provide a good amount of information for the assessment of social-emotional strength and needs of a toddler in clinical practice. CONCLUSION: The C-DECA-T showed good psychometric properties. Our findings of high internal consistency of the three subscales and total score of the C-DECA-T suggest symptom manifestation of social-emotional competence and needs in Taiwanese toddlers is not culturally different from American toddlers. The clinimetric properties of the C-DECA-T examined by a classical test theory analysis approach and an item response theory analysis approach suggest that the C-DECA-T is a reliable and valid instrument for measuring social-emotional strength and needs in the population in Taiwan.

20.
Acta Crystallogr E Crystallogr Commun ; 75(Pt 10): 1540-1543, 2019 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-31636990

RESUMEN

The title phospho-nate-based organic-inorganic hybrid framework, poly[bis(dimethylammonium) [(µ4-2,5-dihydroxybenzene-1,4-diphosphonato)zinc(II)]], {(C2H8N)2[Zn(C6H4O8P2)]} n , was formed unexpectedly when di-methyl-ammonium cations were formed from the in situ deca-rbonylation of the N,N-di-methyl-formamide solvent. The framework is built up from ZnO4 tetra-hedra and bridging di-phospho-nate tetra-anions to generate a three-dimensional network comprising [100] channels occupied by the (CH3)2NH2 + cations. Within the channels, an array of N-H⋯O hydrogen bonds help to establish the structure. In addition, intra-molecular O-H⋯O hydrogen bonds between the appended -OH groups of the phenyl ring and adjacent PO3 2- groups are observed.

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